1. Field of the Invention
The present invention generally relates to integrated circuits, and more particularly to integrating embedded dynamic random access memory (eDRAM) onto the same chip as III-V semiconductor devices.
2. Background of Invention
Embedded dynamic random access memory (eDRAM) is a dynamic random access memory (DRAM) embedded in a logic circuit to function as a high density cache memory. The eDRAM provides comparable access time as static random access memory (SRAM) at a smaller device area per cell. Typically, eDRAM arrays are employed as an L2 level cache or L3 level cache in a processor to provide a high density memory in a processor core. Due to high performance and a compact size, eDRAM has become one of the most efficient means for continued performance of semiconductor logic circuits requiring embedded memory including processors and system-on-chip (SoC) devices.
III-V semiconductor materials have electro-optical and carrier transport properties useful in semiconductor devices. Namely, high electron mobility allowing for increased current drive make III-V materials particularly attractive. Semiconductor devices formed from III-V semiconductor materials, otherwise referred to as III-V semiconductor devices or III-V devices, are promising for high-speed logic devices and for microwave uses. Further, III-V devices have been identified as one potential candidate to aid in the future scaling of integrated circuits.
Compound semiconductors are semiconductor compounds composed of elements from two or more different groups of the Periodic Table of Elements. The term III-V compound semiconductor or III-V semiconductor materials as used throughout the present application, denotes a semiconductor material that includes at least one element from Group 13 (B, Al, Ga, In) and at least one element from Group 15 (N, P, As, Si, Bi) of the Periodic Table of Elements. Typically, the III-V materials are binary, ternary or quaternary alloys including III/V elements. The range of possible formulae is quite broad because these elements can form binary (two elements, e.g., GaAs), ternary (three elements, e.g., InGaAs) and quaternary (four elements, e.g., AlInGaP).